If you have started (or re-started) your application with data collection turned off, then Thread Validator will not collect or show any data.

Thread Validator can display callstacks for sleeping or suspended threads.
 
To do this Thread Validator must hook the SuspendThread, Sleep and SleepEx functions.

Thread Validator will only hook these functions if you enable Functions allocating waitable handles on the Hook Insertion settings dialog and check the required options.

In addition, callstack collection must be enabled. See the Collect and Callstack tabs.

If you have used the Ordinal Handling utility, you may still find the ordinal names have not been converted in symbol names,

•You haven't defined the ordinal to symbol conversion for the correct DLL in which the ordinals are defined

Double check the DLL for which you defined the conversions really include those ordinals.

 
See the topic on Ordinal Handling